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Der:o 8,1925- L564fi85 J. L. KIMBALL DAMPER REGULATOR Filed June 16, 1921 9 ZZVMINVENTOR.

Patented Dec. 8, 1925.

urreo STATES PATENT JAMES LEWIS KIMBALL,

F SALEM, MASSACHUSETTS, ASSIGNOR '10 RUGGLES-KLINGE- MANN MFG. 00., OF SALEM, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

DAMPER REGULATOR.

Application filed June 16, 1921. Serial No. 478,033.

7'0 all "ILILO/IL it may concern:

Be 1t known that 1, JAMES Lnwrs hur- BALL, a citizen of the United States, residing at Salem, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Damper Regulators, of which the following is a specification.

My invention relates to improvements in damper regulators in which a fluid pressure motor is operated by a pressure device by means of a pilot valve and particularly to compensating means for regulators of the above class.

The principal object of my invention is to effect more positive cut-01f action, onabling the fluid pressure motor to assume at alltimes a position which will be consistent with the pressure acting on the pressure device.

A further object of my invention is to provide adjustable means for applying a counteracting force to the scale beam of the pressure device which Will be in proportion to the power required to move the pilot valve.

Another object is to provide means which may be adjusted to effect different pressure variations between the minimum and maximum motor travel.

A still further object is to provide an improved compensating attachment for damper regulators which can be easily and cheaply applied to several standard makes of damper regulators and thereby improve the operation of these regulators,

, I attain these objects in a device arranged as} shown in the accompanying drawing, which represents an elevation of my invention, the fluid-pressure-motor, pilot valve and pressure chamber of the pressure device beingshown in section. The objection to damper regulators of the above type as heretofore constructed is that the cut-oil" point is more or lessindefinite, the motortravel being always more or less in excess of the requirements, or in excess ot the variations 1n pressure acting on the pressure device. The amount of excess movement in any particular regulator depends upon the amount of friction in the pilot valve.- My

' present invention provides means for overcoming this defect so the motor will not travel past the point where it should have stopped.

Referring to the drawing, (1) is a pressure chamber which is closed by a flexible diaphragm (2) apressure cap (3) is mounted on the atmosphere side of the diaphragm and engages a scale beam (4), the scale beam being pivoted at (5) weights (6) are placed on the scale beam to counter-- act the predetermined pressure to be maintained in chamber (1). The above elements constitute a preferred embodiment of a pressure devicefor operating a pilot valve (7). In the operation of this valve a connecting rod (8) is pivoted to the scale beam at (9) the upper end being pivoted at (10) to valve lever (11). One end of valvelever (11) is connected to the pilot valve stem (17) at (12) and the opposite end is pivoted to a link ('13) at (34) whichco-ae ts between the valve lever (11) and a compensating arm (14). Pilot valve (7) has inlet for fluid pressure at (15) and exhaust at (16) the valve stem (17) has cylindrical portions (18) and (19) which control the admission and exhaust of fluid pressure to and from the motor cylinder (20). Port (21) leads to the bottom of the motor and ort (22) to the top of the motor; a piston 23) has piston rod (24) extending through the top cap of the motor; a connecting member (25) 18 secured to the top of the piston rod (24) and provides means for operating the damper. A connecting rod (26) is connected to member (25) at (36), the lower end. being pivoted to the compensating arm (14) at (32). Compensatin arm (14) is free to be rocked on shaft 827% by movementsjof the motor piston (23 a tension spring (28) connects the scale beam (4) with the short end of compensating arm .(14) a screw eye (29) is provided for adjusting the tension on spring (28); and notched positions are provided on the compensating arm and scale beam for shifting the spring to a shorter-arm position. j

It will be understood that any variations of pressure in the pressure chamber (1) above or below a predetermined value will impart motion to the scale beam to operate the pilot valve stem from its neutral posit tion to one-or the other of its effective positions; an increase in pressure admitting fluid pressure to the bottonf of the motor cylinder and venting the top of the cylinder to exhaust while a decrease in pressure will admit fluid pressure to the top of the motor cylinder and vent the bottom to exhaust. It will be understood that the exhaust from the top of the motor cylinder is to the bottom chamber of the pilot valve and is communicated to the exhaust connection (16) through a cored passage which enters at (30) and ends at (31). It will be seen that an increase in ressure will operate the motor piston (23 in an upward direction and a decrease in pressure will operate the piston on a downward stroke. statement of invention, the motor piston should not make a complete stroke on a slight variation of pressure, but should always assume a osition which would be consistent with t e ressure in pressure chamber (1). There ore, means for compensating the action of the motor must be provided. The usual method is that the pressure device moves the pilot valve from its neutral to one or the other of its effective positions which produces a movement of the motor piston which, through suitable mechanism, is arranged to returnthe pilot valve to its neutral position. The amount of travel of the motor piston to efl'ect a return of the pilot valve and bring the motor piston to rest is more or less indefinite, depending on the friction to be overcome in moving the pilot valve.

:Referring to the drawing, it will be seen that an increase in pressure in pressure chamber (1) will raise the scale beam and the pilot valve stem which opens passage (21) to pressure and passage (22) to exhaust, thereby forcing the motor iston (23) upward. It will be seen that t e upward motion of the piston will raise the long end of the compensating arm (14) at point (32) and give a lesser motion to link (13) at point (33) which-is connected to valve lever (11) at (34). Theoretically, such a movement .of the motor plunger should return the pilot valve to its neutral position and bring the motor piston to rest. The valve lever (11) is, however, fulcrumed at or near its centre on the scale beam of the ressure de-. vice. In case of slight friction in the pilot valve, which in avoid, therefore, there will be atendency to raise the scale beam on an upward motion of the motor piston and to depress it on a downward motion. in other words, there is a tendency to shift the ful rum point from the scale beam to the pilot valve stem, the scale beam being moved, more or. less, before": suflicient force can be gathered to move the pilot valve. On a decrease in pressure in pressure chamber (1) the scale beam (4) As explained in the practice it is impossible to meaeee will be depressed, which movement will open passage (22) to pressure and passage (21) to exhaust, which will give a downward motion to the motor piston (23) and a like downward motion to compensating arm (14) at point (32) and a lesser downward motion to link (13) at point (33). Assuming, however, that the scale beam (4) could be held stationary, then the valve lever (11) would be rocked on its fulcrumed point (10), in accordance with theory, to raise valve stem (17) to its neutral position and bring the motor piston to rest.

My resent invention provides novel means or holding the nicely balanced scale beam in a stationary position to permit the motor piston to return the pilot valve to its neutral position. To this end, I have associated with the compensating device a novel equalizing arrangement whereby the abovedescribed tendency of the motor to move the scale beam in a certain direction is counter acted by an equal force in the opposite direction, which I will now explain. The compensating arm (14) being pivoted at (27) and co-acting with valve lever (11) at (33), will have a tendency to raise scale beam (4) on an upward travel of motor piston (23) in proportion to the power required to move the pilot valve stem (.17) downward, as above described. This tendency is counteracted by a downward movement of the compensating arm at the point where spring (28) is attached, such movement relieving the tension of the spring (28) and permitting the weights (6) to exert an increasing d wnward force on the scale beam (4) to ogpose the force exerted by the connecting rd (8) tending to raise the scale beam (4). Thus it will be seen that the position and tension of this spring (28) may be adjusted so that a rocking of the compensating arm (14) on hearing (27) will have no tendency to move the scale beam (4), which will permit the slightest movement of the motor piston (23) to be transmitted direct to the pilot valve stem. ItfWlll be seen that a compensating arrangement such as I have described will enable the motor plunger to assume' a position at ali times which will be consistent with the position of the scale beam.

Another object of my invention is to pro vide means which can be adjusted to effect various pressure ranges between minimum and maximum motor piston travel. It will be understood that the pressure variation acting on dia hragm (2) required to move the piston (23 throughout the entire stroke, will be equivalent to that required to move the scale beam (4) from one extreme of travel to the other, and by increasing the tension on spring (28) va counteracting force in excess of that required to compensate for pilot valve friction can be secured and the pressure variation between extreme limits of travel increased. Under uniform load conditions an operating range of five pounds is usually sufficient, but with extremely fluctuating loads a greater pressure variation must be provided, otherwise the regulator would be of little or no value from a heat efficiency standpoint and means must be provided to effect this increased variation, the object being always, under all load conditions, to hold the damper at a partial stroke, only allowing suflicient air to the furnace to .burn sufiieient fuel to maintain the load on the boilers.

The operation of the regulator, when adjusted for an increased pressure range in excess of that required to compensate for pilot valve friction, is as follows: On an increase of pressure in chamber (1) in ex-' cess o counterweights applied at (6) the scale beam is moved upward and the motor piston assumes a proportionate upward travel, which motion rocks compensating arm- (14), decreasing the tension on spring (28) which allows the counteracting force applied to the scale beam at (6) to become increasingly effective as the piston (23) moves upward from a given stage of travel to the next succeeding stage; and likewise, on a downward stroke, the tension of spring (28) is increased to counteract increasingly the counteracting force of the weights. The total pressure variation between operating limits depends upon the tension and position of the spring co-acting between the compensating arm and the scale beam. Often times it is found desirable to shorten the stroke of the motor piston travel, so that the stroke will conform to that of a certain damper arm to which the regulator is connected. For this purpose, a clamp collar is provided. The higher the clamp collar 35 is mounted upon the piston rod 24, the shorter the stroke of the piston. To adjust the clamp collar 35 upon the piston rod 24, it is necessary first to remove the head at the top of the cylinder. It will be understood, however, that limiting the motor piston travel correspondingly limits the pressure variation required to move the piston from one extreme to the other. Therefore, the advantage of a compensating arrangement which can be adjusted to effect a certain pressure variation between minimum and maximum air supplies of the furnace regardless of stroke required to operate the damper will be apparent. I have shown in the drawing and described in the specifieation an embodiment of a damper regulator which is at present preferred by me, since it has been found to be an improvement in damper regulators as heretofore construct-ed, although it is to be understood that my invention is not limited to the precise arrangement and organization as herein its neutral position.

disclosed. While my invention has been described as a damper regulator and is particularly useful for this purpose, I desire to have it understood that it may be used in other relations, such as the control of fluid pressure valves where it is desired to control the position of the valve from pressure.

)Vhat I claim as my invention and desire to secureby Letters Patent of the United States, is

1. The combination of amotor and a pilot valve, said pilot valve having a neutral position and two effective positions for operating the motor, a pressure device for actuating said pilot valve to either of its effective positions, means operated by the motor for returning the pilot valve to its neutral position upon the motor commencing to act, and means associated with said motor and said pressure device for maintaining an equilibrium of the pressure device during the said return movement of the pilot valve to its neutral position.

2. The combination of a motor and a pilot valve, said pilot valve having a neutral position and two effective positions for operating the motor, a scale beam operated by a diaphragm for actuating said pilot valve to either of its effective positions, said scale beam deriving its movement from variations 95' in pressure, means for counteracting the pressure acting on the scale beam, means operated by the motor for returning the pilot valve to its neutral position'upon the motor commencing to act, and means including a 100 spring and means for adjusting said spring to maintain an equilibrium between the scale beam and its actuating pressure during the said return movement of the pilot valve to its neutral-position.

3. The combination of amotor and a pilot valve, said pilot valve having a neutral position and two effective positions, a pressure device for actuating said pilot valve to either of its effective positions, means operated 110 from the motor for returning the pilot valve to its neutral position, and a spring co-acting between said means and .the pressure device for causing a counteracting force to be exerted upon the pressure device in the op- 115 posite direction to the force exerted on the' pressure device by the said means during the said return movement of the pilot val-veto:

4. The combination of a motor and apilot valve, said pilot valve having a neutral position and two effective positions, a pressure device for actuating said pilot valve to either of its effective positions, compensatmg means operated by the motor for returning the pilot valve to its neutral position, and adjustable means including a spring coacting between the compensating means and the pressure device for causing a force to be exerted on the pressure device for counteracting the force exerted by the compensating means during the said return movement of the pilot valve to its neutral position.

5. The combination of a motor and a pilot valve, said pilot valve having a neutral position and two ell ective positions, a pressure device for actuating said pilot valve to either of its effective positions, compensating means operated by the motor for returning the pilot valve to its neutral position, adjustable means associated with said compensating means including a spring co-acting between the compensating means and the pressure device for causing a variable counteracting force to be exerted on the pressure device in the opposite direction to that exerted by the compensating means during the said return movement of the pilot valve to its neutral position, and means to .adjust the tension on said spring and its position to effect more or less of a pressure variation between the operating limits of the motor.

6. The combination of a motor and a pilot valve, said pilot valve having a neutral position and two eliective positions for operating the motor, a scale beam operated from a diaphragm for actuating said pilot valve to either of its effective positions, said scale beam deriving its movement from variations in pressure, compensating means operated by the motor for returning the pilot valve to its neutral position, said compensating means subjecting the scale beam to a substantially constant force in one direction upon the motor commencing to act, and means including a spring operated by the motor for causing a variable counteracting force to be applied to the scale beam in the opposite direction during the said return movement of the pilot valve to its neutral position.

7. The combination of a motor and a pilot valve, said pilot valve having a neutral position and two elfective positions, a pres sure device for actuating said pilot valve to either of its effective positions, said motor being connected with a compensating arm having a\ stationary pivoted bearing, said arm being. arranged to be rocked on said bearing by' the movement of. the motor, means connected with said compensating arm to return the pilot valve to its neutral position, and a spring co-acting between said compensating arm and said pressure device for exerting a counteracting force to the pressure device in the opposite direction to the force exerted on the pressure device by the rocking of the compensating arm during the said return movement of the pilot valve to its neutral position.

8. In combination, a motor, an element having a neutral position in which it is in effective and an effective position in which the operation ot the motor is adapted to be effected, a device for actuating the element to the effective position, means controlled by the motor for returningthe element to the neutral position, and means tending to maintain the device against actuation during the return movement of the element.

9. In combination, a motor, an element having a neutral position-in which it is ineffective and an eflective position in which the operation of the motor is adapted to be effected, a lever connected to the element, a device connected to the lever to cause the lever to actuate the element to the effective position, means connecting the motor with the lever to cause the lever to return the element to the neutral position, and means tending to maintain the device against actuation during the return movement of the element.

10. In combination, a motor, an element having a neutral position in which it is ineffective and an ellectve position in which the operation of the motor is adapted to be etl'ected, a scale beam connected with the element, a device for actuating the scale beam to etlect a-movement of the element to the effective position, means connecting the motor with the element and the scale beam to tend to return the element to the neutral position and to actuate the scale beam, and means tending to maintain the scale beam against actuation during the return movement ofithe element.

- 11, In a fluid system, a motor for controlling the condition of the fluid in the system, an element having a neutral position in which it is ineiiective and two effective positions in which it is adapted to control the operation of the motor in opposite directions, a scale beam controlled in accordance with the condition of the fluid in the system connected to the element to actuate it to one or the other effective position in accordance with the condition of the fluid in the system, and means connecting the motor with the element to return the e ement to the neutral position andic onnectlng the motor to the scale beam to cause an automatically varying force to be exerted ripen the scale beam to prevent the movement vi the scale beam during the said return movement of the element.

12. In combination, a motor, an element having a neutral position in which it is in ellective and an effective position in which the operation of'the motor is adapted to be effected, a device for actuating the element to the effective position, means controlled by the motor for returning the element to the neutral position, and means for causing the device to aid the return movement of the valve to the neutral position. I

13. In combination, a motor, an element having a neutral sition in which it is ineffective and an e 'ective position in which motor in opposite directions, a device forthe operation of the motor is adapted to be effected, a lever connected to the element, a device connectedto the lever to actuate the element to the effective position, and means connecting the motor to the lever to return the. element to the neutral position and for acting upon the scale beam to aid the return movement of the element to the neutral position.

14. In combination, a motor, an element having a neutral position in which it is ineffective and two effective positions in which it is adapted to control the operation of the motor in opposite directions, a scale beam connected with the element to actuate the element to one or the other effective position, and means connecting the motor with the element to return the element to the neutral position and connecting the motor with the scale beam to cause an automatically varying force to be exerted upon the scale beam adjustable to prevent the movement of the scale beam during the said return movement of the element or to aid the said return movement of the element to the neutral position.

15. In a fluid system, means for controlling the condition of the fluid in the system, an operating member controlled in accordance with the condition of the fluid in the system for controlling the fluid-controlling means, means controlled by the fluidcontrolling means for controlling the fluidcontrolling means, and means connecting the fluid-controlling means and the operating member for maintaining an equilibrium of the operating member.

16. In a fluid system, a motor for controlling the condition of the fluid in the system, an element having a neutral position in which it is ineffective and two eflective positions in which it is adapted to control the operation of the motor in opposite directions, a pressure device controlled in accordance with the condition of the fluid in the system for actuating the element to the effective positions, means controlled by the motor for returning the element to the neutral position, and means tending to maintain the pressure device against actuation during the return movement of the element to the neutral position.

17. In combination, a motor, an element having a neutral position in which itis ineffective and two effective positions in which it is adapted to control the operation of the actuating the element to the effective positions, means controlled by the motor for returning the element to the neutral position, and a yielding connection between the motorcontrolled means and the device for causing acounteracting force to be exerted upon the device opposed to the force exerted by the motor-controlled means, the said yielding connection tending to maintain the device against actuation during the return movement of the element to the neutral position.

tween the compensating means and the device.

19. In combination, a motor, an element having a neutral position in which it is ineffective and an effective position in which the operation of the motor is adapted to be effected, a lever connected with the element, a device connected with the lever to cause the lever to acutate the element to theeffective position, means connecting the motor with the element to cause the motor to return the element to the neutral position, and means connecting the motor with the device to change the setting at which the device will operate to cause a further actuation of the element, the last-named means being effective to produce a change in the setting of the device in all positions of operation of the motor.

20. In a fluid system, a motor for controlling the condition of the fluid in the system, an element having a neutral position in which it isineffective and two effective positions in which it is adapted to control the operation of the motor in opposite directions, a scale beam controlled in accordance with the condition of the fluid in the system, a lever connected with the scale beam and the element, whereby thescale beam is adapted through the lever to actuate the element to one or the other effective position in accordance with the condition of the fluid in the system, means connecting the motor with the lever to cause the lever to eturn the element to the neutral position independently of the operations of the scale beam, and means controlled by the motor for changing the setting at which the scale beam will operate to cause a further actuation of the element, the last named means being effective to produce a change in thesetting of the scale beam in all positions of'operation of the motor.

21. In a pressure regulator, a motor for controlling the-pressure in the system, a controlling element for the motor having a neutral position in which it is ineffective and two effective positions in it is adapted to control the operation of the motor in opposite directions, a lever which the lever to actuate the element to one or the other effective position, and means operated by the motor for returning the element to the neutral position and for causing a varying force to be exerted upon the lever to change the pressure setting of the pressure-responsive device and to aid the motor to return the element to its neutral position.

'22. The combination with a fluid-pressure motor, of a pressure device and a control-' ling valve for operating the motor, an operating member for said valve, means connecting said valve and said operating member, means co-acting between. the first-named means and the fluid-pressure motor for shifting the controlling valve from an effective to a non-effective position, and means co-acting between the second-named means and the operating member for maintaining an equilibrium of the ressure device While said valve is being shi ted.

23. In a pressure system, a motor for controlling the pressure in the system, a valve 1 for controlling the motor, a pressure device controlled in accordance with the pressure in the system, a connection between the pressure device and the valve for efiecting an opening oil the valve in response to a variation in pressure, com ensating means controlled by the motor or closing the valve, and means for counteracting the efi'ect produced upon the pressure device by the said variation in pressure without affecting the operation of the valve.

24. In a fluid system, a motor for con trolling the condition of the fluid in the sys-v tem, two elements having a relative neutral position in which they are ineffective and a relative effective position in which they control the operation of. the motor, a device controlledin accordance with the condition of the fluid'in the system for relatively actuating the elements to the relative effective position in response to a variation in the condition of the fluid in the system, compensating means controlled by the motor for relatively returning the elements to the relative neutral position, and means for counteracting the efi'ect produced upon the device by the said variation in the condition of the fluid in the system without affooting the operation of the elements.

In testimony whereof l-have affixed my signature.

JAMES LEWIS KIMBALL. 

